With the expansion of the US ethanol industry, the amount of grain byproducts on the market has increased. Sorghum is the second most common grain used in ethanol production, yet few studies have evaluated lactating dairy cow performance when fed distillers grains with solubles (DGS) from grain sources other than corn. Studies evaluating sorghum-based DGS in finishing cattle have reported variable results. Inconsistent findings may be the result of differences in the quality and quantity of solubles added back to the DGS, technology differences used at the ethanol plants, physical form, and DGS inclusion rates. The objective of this study, conducted on a commercial dairy farm in Wisconsin, was to evaluate the effects of sorghum dried DGS (SDGS) compared with corn dried DGS (CDGS) when fed at 8% of dietary DM. Multiparous (μ = 3) Holstein cows (n = 362; 132 ± 2.8 DIM) were allocated to 1 of 3 pens based on DIM and milk yield. For comparison, a negative control pen was fed a diet that contained 3.6% corn dried distillers grains with solubles (CON). All diets were formulated to be isonitrogenous and isocaloric. Milk samples were collected and analyzed by DHIA on d 14 and 28. The MIXED procedure of SAS 9.4 (SAS Institute Inc., Cary, NC) was used to evaluate fixed effect of diet. No effect of dietary treatment existed for daily milk yield (P = 0.59) or percent milk protein (P = 0.69) from CON (52.9 ± 0.84 kg/d and 3.00 ± 0.008%, respectively), SDGS (52.2 ± 0.83 kg/d and 3.00 ± 0.008%, respectively), or CDGS (52.7 ± 0.84 kg/d and 3.01 ± 0.008%, respectively). Percent milk fat was greater (P < 0.05) from CDGS (3.63 ± 0.023%) compared with CON (3.49 ± 0.023%) or SDGS (3.55 ± 0.023%). An effect of dietary treatment existed on DM intake (P < 0.01), where intake was less (P < 0.05) for cows consuming CON (27.8 ± 0.19 kg/d) compared with SDGS (28.9 ± 0.19 kg/d) and CDGS (29.0 ± 0.19 kg/d) which were not different (P > 0.05). Results indicate that inclusion of SDGS in the diet of lactating dairy cows should not negatively afect overall animal performance when compared with CDGS.